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fixing nls

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2018-03-13 17:23:58 -07:00
parent 4375f54c45
commit bf8ea92b99
2 changed files with 50 additions and 27 deletions
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59
src/opt/opt_lns.cpp
View file

@ -28,7 +28,8 @@ namespace opt {
m(ctx.get_manager()),
m_ctx(ctx),
m_solver(s),
m_models_trail(m)
m_models_trail(m),
m_atoms(m)
{}
lns::~lns() {}
@ -42,9 +43,19 @@ namespace opt {
lbool lns::operator()() {
if (m_queue.empty()) {
expr_ref_vector lits(m);
expr_ref_vector lits(m), atoms(m);
m_ctx.get_lns_literals(lits);
m_queue.push_back(queue_elem(lits));
for (expr* l : lits) {
expr* nl = nullptr;
if (m.is_not(l, nl)) {
m_atoms.push_back(nl);
}
else {
atoms.push_back(l);
m_atoms.push_back(l);
}
}
m_queue.push_back(queue_elem(atoms));
m_qhead = 0;
}
@ -54,34 +65,47 @@ namespace opt {
m_solver->updt_params(p);
while (m_qhead < m_queue.size()) {
unsigned index = m_queue[m_qhead].m_index;
if (index > m_queue[m_qhead].m_assignment.size()) {
++m_qhead;
obj_hashtable<expr> atoms;
for (expr* f : m_queue[m_qhead].m_assignment) {
atoms.insert(f);
}
unsigned& index = m_queue[m_qhead].m_index;
expr* lit = nullptr;
for (; index < m_atoms.size() && (lit = m_atoms[index].get(), (atoms.contains(lit) || m_units.contains(lit))); ++index) ;
if (index == m_atoms.size()) {
m_qhead++;
continue;
}
IF_VERBOSE(2, verbose_stream() << "(opt.lns :queue " << m_qhead << " :index " << index << ")\n");
// recalibrate state to an initial satisfying assignment
lbool is_sat = m_solver->check_sat(m_queue[m_qhead].m_assignment);
IF_VERBOSE(2, verbose_stream() << "(opt.lns :calibrate-status " << is_sat << ")\n");
expr_ref lit(m_queue[m_qhead].m_assignment[index].get(), m);
lit = mk_not(m, lit);
expr* lits[1] = { lit };
++m_queue[m_qhead].m_index;
if (!m.limit().inc()) {
return l_undef;
}
expr* lit = m_atoms[index].get();
expr_ref_vector lits(m);
lits.push_back(lit);
++index;
// Update configuration for local search:
// p.set_uint("sat.local_search_threads", 2);
// p.set_uint("sat.unit_walk_threads", 1);
is_sat = m_solver->check_sat(1, lits);
IF_VERBOSE(2, verbose_stream() << "(opt.lns :status " << is_sat << ")\n");
is_sat = m_solver->check_sat(lits);
IF_VERBOSE(2, verbose_stream() << "(opt.lns :lookahead-status " << is_sat << " " << lit << ")\n");
if (is_sat == l_true && add_assignment()) {
return l_true;
}
if (is_sat == l_false) {
m_units.insert(lit);
}
if (!m.limit().inc()) {
return l_undef;
}
}
return l_false;
}
@ -92,13 +116,10 @@ namespace opt {
m_ctx.fix_model(mdl);
expr_ref tmp(m);
expr_ref_vector fmls(m);
for (expr* f : m_queue[0].m_assignment) {
for (expr* f : m_atoms) {
mdl->eval(f, tmp);
if (m.is_false(tmp)) {
fmls.push_back(mk_not(m, tmp));
}
else {
fmls.push_back(tmp);
if (m.is_true(tmp)) {
fmls.push_back(f);
}
}
tmp = mk_and(fmls);

18
src/opt/opt_lns.h
View file

@ -36,15 +36,17 @@ namespace opt {
m_index(0)
{}
};
ast_manager& m;
context& m_ctx;
ref<solver> m_solver;
model_ref m_model;
svector<symbol> m_labels;
vector<queue_elem> m_queue;
unsigned m_qhead;
expr_ref_vector m_models_trail;
ast_manager& m;
context& m_ctx;
ref<solver> m_solver;
model_ref m_model;
svector<symbol> m_labels;
vector<queue_elem> m_queue;
unsigned m_qhead;
expr_ref_vector m_models_trail;
expr_ref_vector m_atoms;
obj_hashtable<expr> m_models;
obj_hashtable<expr> m_fixed;
bool add_assignment();
public: